As a technology for reducing packet collisions in a multi-hop network, a wireless network is known in which a first wireless network group transmits packets in a first time point and then a second wireless network group transmits packets at a second time point. By thus transmitting packets in a slide scheme, packet collisions due to transmission of packets at the same time point can be avoided.
Related art is disclosed in Japanese National Publication of International Patent Application No. 2010-171917.